Systems and methods for refrigerating crops and other goods and for defrosting a refrigeration system. A refrigerant is circulated between a condenser and a refrigerator to cool air in the refrigerator. Heat is removed from the refrigerant at the condenser. Periodically the cycle of refrigerant and air can be reversed to melt frost in the refrigerator. Frost can be detected by a sensing mechanism and the refrigerant and air cycles can be reversed in response to detecting the frost. The frost can be removed quickly without removing the goods from the refrigerant.